:root {
  --bg: #f7f4ef;
  --card: #ffffff;
  --text: #1f2933;
  --muted: #5f6b77;
  --accent: #315f50;
  --accent-dark: #24483d;
  --border: #ded8cf;
  --soft: #eee7dc;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.5;
}

.site-header {
  max-width: 1040px;
  margin: 0 auto;
  padding: 18px 20px;
}

.logo {
  color: var(--text);
  font-weight: 800;
  text-decoration: none;
}

main {
  max-width: 1040px;
  margin: 0 auto;
  padding: 0 20px 50px;
}

.hero {
  padding: 44px 0 24px;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--accent);
  font-size: .8rem;
  font-weight: 800;
  letter-spacing: .08em;
  text-transform: uppercase;
}

h1 {
  max-width: 760px;
  margin: 0;
  font-size: clamp(2.4rem, 7vw, 5rem);
  line-height: .95;
  letter-spacing: -0.055em;
}

.lead {
  max-width: 680px;
  margin: 20px 0 0;
  color: var(--muted);
  font-size: clamp(1.05rem, 2vw, 1.25rem);
}

.calculator-card, .content-section {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 22px;
  padding: clamp(20px, 4vw, 34px);
  box-shadow: 0 16px 40px rgba(31, 41, 51, .06);
  margin: 24px 0;
}

.calculator-card h2, .content-section h2 {
  margin-top: 0;
  font-size: clamp(1.45rem, 3vw, 2rem);
  letter-spacing: -0.035em;
}

.form-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

label, legend {
  font-weight: 750;
}

select {
  display: block;
  width: 100%;
  margin-top: 8px;
  padding: 13px 14px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: #fff;
  color: var(--text);
  font-size: 1rem;
}

fieldset {
  margin: 22px 0;
  padding: 18px;
  border: 1px solid var(--border);
  border-radius: 16px;
}

.checkbox-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px 18px;
  margin-top: 12px;
}

.checkbox-grid label {
  font-weight: 600;
}

input[type="checkbox"] {
  margin-right: 8px;
  transform: scale(1.1);
}

button {
  width: 100%;
  border: 0;
  border-radius: 14px;
  padding: 16px 20px;
  background: var(--accent);
  color: #fff;
  font-size: 1.05rem;
  font-weight: 850;
  cursor: pointer;
}

button:hover, button:focus { background: var(--accent-dark); }

.results {
  margin-top: 26px;
  padding: 22px;
  border-radius: 18px;
  background: var(--soft);
}

.hidden { display: none; }

.result-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin: 18px 0;
}

.result-item {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 14px;
}

.result-item strong {
  display: block;
  font-size: 1.55rem;
}

.note {
  color: var(--muted);
  font-size: .95rem;
}

.two-column {
  display: grid;
  grid-template-columns: 1.3fr .7fr;
  gap: 22px;
}

.sponsor-box {
  background: var(--soft);
  border-radius: 18px;
  padding: 20px;
}

.sponsor-box h3 { margin-top: 0; }

ul { padding-left: 1.2rem; }

details {
  border-top: 1px solid var(--border);
  padding: 16px 0;
}

details:last-child { border-bottom: 1px solid var(--border); }

summary {
  cursor: pointer;
  font-weight: 800;
}

footer {
  max-width: 1040px;
  margin: 0 auto;
  padding: 28px 20px 45px;
  color: var(--muted);
  font-size: .95rem;
}

footer a { color: var(--accent); }

@media (max-width: 720px) {
  .form-grid,
  .checkbox-grid,
  .result-grid,
  .two-column {
    grid-template-columns: 1fr;
  }

  .hero { padding-top: 28px; }
}